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Date: Mon, 25 Dec 2006 14:00:12 -0700
From: Bob White <rlwhite@comcast.net>
To: "Rotary motors in aircraft" <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: fuel pumps
Message-Id: <20061225140012.d52c9380.rlwhite@comcast.net>
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On Mon, 25 Dec 2006 14:26:15 EST
Lehanover@aol.com wrote:

>  
> In a message dated 12/25/2006 2:06:43 P.M. Eastern Standard Time,  
> grdflyguy@yahoo.com writes:
> 
> Is it  common procedure to use both fuel pumps on for
> take off & landing? Its  great redundency, however, Im
> concerned there may be to much  fuel  pressure.
> 
> Lou
> 
> 
> 
> Plumbed in series (one pump feeding the second pump) would about double the  
> pressure.
>  
> Plumbed in parallel (more common) the pressure remains the same as the  
> strongest pump.
>  
> Lynn E. Hanover
> 

The pressure in the fuel rail is set by the regulator.  My pumps (from
Tracy) can put out about 90 psi, but the rail pressure is 45 psi.  The
regulators aren't perfect.  I see about 45 PSI with either single pump
on and 48 or so with both pumps on with a parallel setup. That's
measured at the Aeromotive A1000 regulator. It will run a little richer
with both pumps on but not enough to cause any problems.

I use both pumps for take-off - (both of them).

Bob W. (That's both take-off's if that wasn't clear.)

-- 
N93BD - Rotary Powered BD-4 - http://www.bob-white.com
First Flight:  11/23/2006 7:50AM - 0.7 Hours Total Time
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